/*
 * Copyright 2011 Clean GWT
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */
package com.cleangwt.json.client;

import java.util.Map;

import com.google.gwt.json.client.JSONObject;
import com.google.gwt.json.client.JSONValue;

/**
 * The {@link Map}<{@code String},{@code Object}> json serializer.
 * 
 * @author Jess
 * @version 1.0
 * @since 1.0
 */
public class MapSerializer extends JsonValueSerializer<Map<String, Object>> {
  private static MapSerializer impl;

  /**
   * @return the instance of {@link Map} serializer
   */
  public static MapSerializer get() {
    if (impl == null) {
      impl = new MapSerializer();
    }
    return impl;
  }

  private MapSerializer() {
  }

  @Override
  public JSONValue toJson(Map<String, Object> value) {
    JSONObject jsonObject = new JSONObject();
    for (String key : value.keySet()) {
      Object v = value.get(key);
      if (v != null) {
        jsonObject.put(key, ObjectSerializer.get().toJson(v));
      }
    }
    return jsonObject;
  }
}
